1. Field of the Invention
The present invention generally relates to scheduler, and more particularly to preemptive weighted round robin scheduler.
2. Description of the Prior Art
In conventional arbitration scheme, the strict (real time) traffic could be served by different priority scheme like high/low queues, but it cannot use the bandwidth in fair and efficient way even more it could cause starvation if no proper scheme to avoid. The WRR, weighted round robin, scheme scans the weight of all requests in a predefined order to decide which request could grant the service and the corresponding weight is adjusted after service, for certain request there is no guarantee to preempt other request even user want to, this scheme could provide controllable bandwidth among all requests under fair behavior without starvation hazard. On contrast to high/low queues, the WRR scheme could provide faired bandwidth usage but could not preempt bandwidth for critical traffics.
Summarized, there is a need for a scheduling method and system to support both preemptive and non-preemptive traffics with faired and efficient bandwidth utilization.